Mobile device and optical imaging lens thereof

ABSTRACT

Present embodiments provide for a mobile device and an optical imaging lens thereof. The optical imaging lens comprises five lens elements positioned sequentially from an object side to an image side. Through controlling the convex or concave shape of the surfaces, the refracting power of the lens elements and parameters to meet an inequality associated with the effective focal length, the optical imaging lens shows better optical characteristics and the total length of the optical imaging lens is shortened.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 16/867,808, filed May 6, 2020, which is a continuation of U.S. application Ser. No. 16/506,903, filed Jul. 9, 2019, which is a continuation of U.S. application Ser. No. 15/376,452, filed on Dec. 12, 2016, now U.S. Pat. No. 10,394,001, which is a continuation of U.S. application Ser. No. 14/094,512, entitled “Mobile Device and Optical Imaging Lens Thereof” filed on Dec. 2, 2013, now U.S. Pat. No. 9,541,736, which claims priority from P.R.C. Patent Application No. 201310288831.9, filed on Jul. 10, 2013, the contents of which are hereby incorporated by reference in their entirety for all purposes.

FIELD OF THE INVENTION

The present invention relates to a mobile device and an optical imaging lens thereof, and particularly, relates to a mobile device applying an optical imaging lens having five lens elements and an optical imaging lens thereof.

BACKGROUND OF THE INVENTION

Dimension reduction is the major consideration for designing an optical imaging lens in recent years. When reducing the length of the optical imaging lens, however, achieving good optical characteristics becomes a challenging problem.

U.S. Pat. Nos. 7,502,181, 7,826,151 and 8,422,145 all disclosed an optical imaging lens constructed with an optical imaging lens having five lens elements. In these patents, the aperture stop is positioned before the first lens element, and the transition of refracting power of the first two lens elements is positive-negative. However, such configurations still fail to satisfy users' needs for a better imaging quality and thinner and slimmer design, because the HFOV (half of field of view) in these patents is merely 32 to 33 degrees and the lengths of the optical imaging lenses thereof fall into the range of 6.5 to 8.0 mm.

Therefore, there is needed to develop optical imaging lens with a shorter length, while also having good optical characters.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a mobile device and an optical imaging lens thereof. With controlling the convex or concave shape of the surfaces, the refracting power of the lens elements and two parameters to meet an inequality associated with the thickness of the second lens element, the length of the optical imaging lens is shortened and meanwhile the good optical characters, and system functionality are sustained.

In an exemplary embodiment, an optical imaging lens comprises, sequentially from an object side to an image side along an optical axis, comprises a first lens element, an aperture stop, a second lens element, a third lens element, a fourth lens element and a fifth lens element, each of the first, second, third, fourth and fifth lens elements having refracting power, an object-side surface facing toward the object side and an image-side surface facing toward the image side, wherein: the object-side surface of the first lens element is a convex surface; the second lens element has positive refracting power; the image-side surface of the fifth lens element comprises a concave portion in a vicinity of the optical axis and a convex portion in a vicinity of a periphery of the fifth lens element; the optical imaging lens as a whole comprises only the five lens elements having refracting power and satisfies an inequality associated with the thickness of the second lens element. The inequality is one of the follows:

T2/AG23≤2.5  Equation (1); or

T2/T3≤1.2  Equation (2); or

T2/AG12≤5.3  Equation (3);

a central thickness of the second lens element along the optical axis is T2, a central thickness of the third lens element along the optical axis is T3, an air gap between the first lens element and the second lens element along the optical axis is AG12 and an air gap between the second lens element and the third lens element along the optical axis is AG23.

In another exemplary embodiment, some equation(s), such as those relating to the ratio among parameters could be taken into consideration. For example, T3 and a central thickness of the fourth lens element along the optical axis, T4, could be controlled to satisfy the equation as follows:

T4/T3≤1.8  Equation (4); or

The sum of the thickness of all five lens elements along the optical axis, ALT, and the sum of all four air gaps from the first lens element to the fifth lens element along the optical axis, AAG, could be controlled to satisfy the equation as follows:

ALT/AAG≤3.5  Equation (5); or

AG23 and a central thickness of the fifth lens element along the optical axis, T5, could be controlled to satisfy the equation as follows:

T5/AG23≤2.0  Equation (6); or

T4 and AG23 could be controlled to satisfy the equation as follows:

T4/AG23≤4.0  Equation (7); or

AG23 and ALT could be controlled to satisfy the equation as follows:

ALT/AG23≤10.0  Equation (8); or

AAG, an air gap between the third lens element and the fourth lens element along the optical axis, AG34, and an air gap between the fourth lens element and the fifth lens element along the optical axis, AG45, could be controlled to satisfy the equation as follows:

4.5≤AAG/(AG34+AG45)  Equation (9); or

AG12 and a central thickness of the first lens element along the optical axis, T1, could be controlled to satisfy the equation as follows:

T1/AG12≤2.8  Equation (10); or

0.4≤T1/AG12≤2.8  Equation (10′); or

T4 and AG12 could be controlled to satisfy the equation as follows:

T4/AG12≤2.0  Equation (11); or

T3 and ALT could be controlled to satisfy the equation as follows:

3.5≤ALT/T3≤6.0  Equation (12); or

T4 and T5 could be controlled to satisfy the equation as follows:

0.8≤T5/T4  Equation (13); or

AAG and T4 could be controlled to satisfy the equation as follows:

1.7≤AAG/T4  Equation (14).

Aforesaid exemplary embodiments are not limited and could be selectively incorporated in other embodiments described herein.

In some exemplary embodiments, more details about the convex or concave surface structure or the refracting power of the lens element(s) could be incorporated for one specific lens element or broadly for plural lens elements to enhance the control for the system performance and/or resolution. For example, the object-side surface of the second lens element may further comprise a concave portion in a vicinity of a periphery of the second lens element, the object-side surface of the third lens element may further comprise a concave portion in a vicinity of the optical axis, the image-side surface of said third lens element comprises a convex portion in a vicinity of the optical axis, the object-side surface of the fourth lens element may further comprise a convex portion in a vicinity of the optical axis and/or the fifth lens element may have positive refracting power, etc. It is noted that the details could be incorporated in example embodiments if no inconsistency occurs.

In another exemplary embodiment, a mobile device comprising a housing and a photography module positioned in the housing is provided. The photography module comprises any of aforesaid example embodiments of optical imaging lens, a lens barrel, a module housing unit, a substrate and an image sensor. The lens barrel is for positioning the optical imaging lens, the module housing unit is for positioning the lens barrel, the substrate is for positioning the module housing unit; and the image sensor is positioned on the substrate and at the image side of the optical imaging lens.

Through controlling the convex or concave shape of the surfaces, the refracting power of the lens element(s) and two parameters to meet an inequality associated with the thickness of the second lens element, the mobile device and the optical imaging lens thereof in exemplary embodiments achieve good optical characters and effectively shorten the length of the optical imaging lens.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which:

FIG. 1 is a cross-sectional view of one single lens element according to the present disclosure;

FIG. 2 is a cross-sectional view of a first embodiment of an optical imaging lens having five lens elements according to the present disclosure;

FIG. 3 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a first embodiment of the optical imaging lens according to the present disclosure;

FIG. 4 is a table of optical data for each lens element of a first embodiment of an optical imaging lens according to the present disclosure;

FIG. 5 is a table of aspherical data of a first embodiment of the optical imaging lens according to the present disclosure;

FIG. 6 is a cross-sectional view of a second embodiment of an optical imaging lens having five lens elements according to the present disclosure;

FIG. 7 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a second embodiment of the optical imaging lens according to the present disclosure;

FIG. 8 is a table of optical data for each lens element of the optical imaging lens of a second embodiment of the present disclosure;

FIG. 9 is a table of aspherical data of a second embodiment of the optical imaging lens according to the present disclosure;

FIG. 10 is a cross-sectional view of a third embodiment of an optical imaging lens having five lens elements according to the present disclosure;

FIG. 11 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a third embodiment of the optical imaging lens according the present disclosure;

FIG. 12 is a table of optical data for each lens element of the optical imaging lens of a third embodiment of the present disclosure;

FIG. 13 is a table of aspherical data of a third embodiment of the optical imaging lens according to the present disclosure;

FIG. 14 is a cross-sectional view of a fourth embodiment of an optical imaging lens having five lens elements according to the present disclosure;

FIG. 15 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a fourth embodiment of the optical imaging lens according the present disclosure;

FIG. 16 is a table of optical data for each lens element of the optical imaging lens of a fourth embodiment of the present disclosure;

FIG. 17 is a table of aspherical data of a fourth embodiment of the optical imaging lens according to the present disclosure;

FIG. 18 is a cross-sectional view of a fifth embodiment of an optical imaging lens having five lens elements according to the present disclosure;

FIG. 19 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a fifth embodiment of the optical imaging lens according the present disclosure;

FIG. 20 is a table of optical data for each lens element of the optical imaging lens of a fifth embodiment of the present disclosure;

FIG. 21 is a table of aspherical data of a fifth embodiment of the optical imaging lens according to the present disclosure;

FIG. 22 is a cross-sectional view of a sixth embodiment of an optical imaging lens having five lens elements according to the present disclosure;

FIG. 23 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a sixth embodiment of the optical imaging lens according the present disclosure;

FIG. 24 is a table of optical data for each lens element of the optical imaging lens of a sixth embodiment of the present disclosure;

FIG. 25 is a table of aspherical data of a sixth embodiment of the optical imaging lens according to the present disclosure;

FIG. 26 is a cross-sectional view of a seventh embodiment of an optical imaging lens having five lens elements according to the present disclosure;

FIG. 27 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a seventh embodiment of the optical imaging lens according the present disclosure;

FIG. 28 is a table of optical data for each lens element of the optical imaging lens of a seventh embodiment of the present disclosure;

FIG. 29 is a table of aspherical data of a seventh embodiment of the optical imaging lens according to the present disclosure;

FIG. 30 is a cross-sectional view of a eighth embodiment of an optical imaging lens having five lens elements according to the present disclosure;

FIG. 31 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a eighth embodiment of the optical imaging lens according the present disclosure;

FIG. 32 is a table of optical data for each lens element of the optical imaging lens of a eighth embodiment of the present disclosure;

FIG. 33 is a table of aspherical data of a eighth embodiment of the optical imaging lens according to the present disclosure;

FIG. 34 is a cross-sectional view of a ninth embodiment of an optical imaging lens having five lens elements according to the present disclosure;

FIG. 35 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a ninth embodiment of the optical imaging lens according the present disclosure;

FIG. 36 is a table of optical data for each lens element of the optical imaging lens of a ninth embodiment of the present disclosure;

FIG. 37 is a table of aspherical data of a ninth embodiment of the optical imaging lens according to the present disclosure;

FIG. 38 is a cross-sectional view of a tenth embodiment of an optical imaging lens having five lens elements according to the present disclosure;

FIG. 39 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a tenth embodiment of the optical imaging lens according the present disclosure;

FIG. 40 is a table of optical data for each lens element of the optical imaging lens of a tenth embodiment of the present disclosure;

FIG. 41 is a table of aspherical data of a tenth embodiment of the optical imaging lens according to the present disclosure;

FIG. 42 is a cross-sectional view of a eleventh embodiment of an optical imaging lens having five lens elements according to the present disclosure;

FIG. 43 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a eleventh embodiment of the optical imaging lens according the present disclosure;

FIG. 44 is a table of optical data for each lens element of the optical imaging lens of a eleventh embodiment of the present disclosure;

FIG. 45 is a table of aspherical data of a eleventh embodiment of the optical imaging lens according to the present disclosure;

FIG. 46 is a table for the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 of all eleventh example embodiments;

FIG. 47 is a structure of an example embodiment of a mobile device;

FIG. 48 is a partially enlarged view of the structure of another example embodiment of a mobile device.

DETAILED DESCRIPTION OF THE INVENTION

For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features. Persons having ordinary skill in the art will understand other varieties for implementing example embodiments, including those described herein. The drawings are not limited to specific scale and similar reference numbers are used for representing similar elements. As used in the disclosures and the appended claims, the terms “example embodiment,” “exemplary embodiment,” and “present embodiment” do not necessarily refer to a single embodiment, although it may, and various example embodiments may be readily combined and interchanged, without departing from the scope or spirit of the present invention. Furthermore, the terminology as used herein is for the purpose of describing example embodiments only and is not intended to be a limitation of the invention. In this respect, as used herein, the term “in” may include “in” and “on”, and the terms “a”, “an” and “the” may include singular and plural references. Furthermore, as used herein, the term “by” may also mean “from”, depending on the context. Furthermore, as used herein, the term “if” may also mean “when” or “upon”, depending on the context. Furthermore, as used herein, the words “and/or” may refer to and encompass any and all possible combinations of one or more of the associated listed items.

Here in the present specification, “a lens element having positive refracting power (or negative refracting power)” means that the lens element has positive refracting power (or negative refracting power) in the vicinity of the optical axis. “An object-side (or image-side) surface of a lens element comprises a convex (or concave) portion in a specific region” means that the object-side (or image-side) surface of the lens element “protrudes outwardly (or depresses inwardly)” along the direction parallel to the optical axis at the specific region, compared with the outer region radially adjacent to the specific region. Taking FIG. 1 for example, the lens element shown therein is radially symmetric around the optical axis which is labeled by I. The object-side surface of the lens element comprises a convex portion at region A, a concave portion at region B, and another convex portion at region C. This is because compared with the outer region radially adjacent to the region A (i.e. region B), the object-side surface protrudes outwardly at the region A, compared with the region C, the object-side surface depresses inwardly at the region B, and compared with the region E, the object-side surface protrudes outwardly at the region C. Here, “in a vicinity of a periphery of a lens element” means that in a vicinity of the peripheral region of a surface for passing imaging light on the lens element, i.e. the region C as shown in FIG. 1. The imaging light comprises chief ray Lc and marginal ray Lm. “In a vicinity of the optical axis” means that in a vicinity of the optical axis of a surface for passing the imaging light on the lens element, i.e. the region A as shown in FIG. 1. Further, a lens element could comprise an extending portion E for mounting the lens element in an optical imaging lens. Ideally, the imaging light would not pass the extending portion E. Here the extending portion E is only for example, the structure and shape thereof are not limited to this specific example. Please also noted that the extending portion of all the lens elements in the example embodiments shown below are skipped for maintaining the drawings clean and concise.

Example embodiments of an optical imaging lens may comprise a first lens element, an aperture stop, a second lens element, a third lens element, a fourth lens element and a fifth lens element, each of the lens elements comprises refracting power, an object-side surface facing toward an object side and an image-side surface facing toward an image side. These lens elements may be arranged sequentially from the object side to the image side along an optical axis, and example embodiments of the lens as a whole may comprise only the five lens elements having refracting power. In an example embodiment: the object-side surface of the first lens element is a convex surface; the second lens element has positive refracting power; the image-side surface of the fifth lens element comprises a concave portion in a vicinity of the optical axis and a convex portion in a vicinity of a periphery of the fifth lens element; and the optical imaging lens satisfies an inequality associated with the thickness of the second lens element. The inequality is one of the follows:

T2/AG23≤2.5  Equation (1); or

T2/T3≤1.2  Equation (2); or

T2/AG12≤5.3  Equation (3);

a central thickness of the second lens element along the optical axis is T2, a central thickness of the third lens element along the optical axis is T3, an air gap between the first lens element and the second lens element along the optical axis is AG12 and an air gap between the second lens element and the third lens element along the optical axis is AG23.

Preferably, the lens elements are designed in light of the optical characteristics and the length of the optical imaging lens. For example, the second lens element having positive refracting power provides the positive refracting power required in the optical imaging lens, the aperture stop positioned between the first and second lens elements enlarges the HFOV and assists in eliminating the aberration of the optical imaging lens, and the concave portion in the vicinity of the optical axis and the convex portion in a vicinity of a periphery of the fifth lens element assists in adjust the emitting angle of the light onto the imaging plane to reduce the field curvature aberration. If the refracting power of the fifth lens element is positive to share burden of the positive refracting power required in the optical imaging lens with the second lens element, the sensitivity in the manufacture process will be lowered. Further with some details of shape on the surfaces of the lens elements, such as the concave portion in a vicinity of a periphery of the second lens element on the object-side surface thereof, the concave portion in a vicinity of the optical axis on the object-side surface of the third lens element, the convex portion in a vicinity of the optical axis on the image-side surface of the third lens element and/or the convex portion in a vicinity of the optical axis on the object-side surface of the fourth lens element, the image quality of the whole system could be further promoted.

In another exemplary embodiment, some equation(s) of parameters, such as those relating to the ratio among parameters could be taken into consideration. For example, T3 and a central thickness of the fourth lens element along the optical axis, T4, could be controlled to satisfy the equation as follows:

T4/T3≤1.8  Equation (4); or

The sum of the thickness of all five lens elements along the optical axis, ALT, and the sum of all four air gaps from the first lens element to the fifth lens element along the optical axis, AAG, could be controlled to satisfy the equation as follows:

ALT/AAG≤3.5  Equation (5); or

AG23 and a central thickness of the fifth lens element along the optical axis, T5, could be controlled to satisfy the equation as follows:

T5/AG23≤2.0  Equation (6); or

T4 and AG23 could be controlled to satisfy the equation as follows:

T4/AG23≤4.0  Equation (7); or

AG23 and ALT could be controlled to satisfy the equation as follows:

ALT/AG23≤10.0  Equation (8); or

AAG, an air gap between the third lens element and the fourth lens element along the optical axis, AG34, and an air gap between the fourth lens element and the fifth lens element along the optical axis, AG45, could be controlled to satisfy the equation as follows:

4.5≤AAG/(AG34+AG45)  Equation (9); or

AG12 and a central thickness of the first lens element along the optical axis, T1, could be controlled to satisfy the equation as follows:

T1/AG12≤2.8  Equation (10); or

0.4≤T1/AG12≤2.8  Equation (10′); or

T4 and AG12 could be controlled to satisfy the equation as follows:

T4/AG12≤2.0  Equation (11); or

T3 and ALT could be controlled to satisfy the equation as follows:

3.5≤ALT/T3≤6.0  Equation (12); or

T4 and T5 could be controlled to satisfy the equation as follows:

0.8≤T5/T4  Equation (13); or

AAG and T4 could be controlled to satisfy the equation as follows:

1.7≤AAG/T4  Equation (14).

Aforesaid exemplary embodiments are not limited and could be selectively incorporated in other embodiments described herein.

Reference is now made to Equations (1), (2) and (3). Here these three equations are designed to limit a ratio regarding to the thickness of the second lens element in a certain range in light of that it is the second lens element providing the main positive refracting power required in the optical imaging lens. Therefore, if the thickness of the second lens element is reduced, the length of the optical imaging lens is also shortened. On the contrary, there are some parameters which are less likely to be shortened or not the major targets to be shortened, and such parameters are used in the Equations (1), (2) and (3) respectively for controlling the optical characters of the optical imaging lens. Then, the optical imaging lens may achieve good optical characters with a shortened length.

Reference is now made to Equation (1). This equation is design in light of the desirable small T2 and the large air gap between the second and third lens elements which will allow that the light spreads to a desirable level and then enters into the third lens element. If this is true, the image quality will be better. Therefore, the smaller value of T2/AG23 is desirable. The value of T2/AG23 is preferably smaller than or equal to 2.5 to satisfy Equation (1), and more preferably, the value of T2/AG23 is suggested for a lower limit, such as 0.6.

Reference is now made to Equation (2). This equation is design in light of the desirable small T2 and the thickness of the third lens element is required for a certain value. Therefore, the smaller value of T2/T3 is desirable. The value of T2/T3 is preferably less than or equal to 1.2 to satisfy Equation (2), and more preferably, the value of T2/T3 is suggested for a lower limit, such as 0.5.

Reference is now made to Equation (3). This equation is design in light of the desirable small T2 and the air gap between the first and second lens elements is required for a certain value to receive the aperture stop. Therefore, the smaller value of T2/AG12 is desirable. The value of T2/AG12 is preferably less than or equal to 5.3 to satisfy Equation (3), and more preferably, the value of T2/AG12 is suggested for a lower limit, such as 0.5.

Then, here are our considerations for designing Equations (4)-(14):

Reference is now made to Equation (4). The values of T3 and T4 will be properly configured if the thickness of the fourth lens element is as thin as possible but the thickness of the third lens element is sustained to a certain value. Therefore, the value of T4/T3 is preferably less than or equal to 1.8 to satisfy Equation (4), and more preferably, the value of T4/T3 is suggested for a lower limit, such as 0.2.

Reference is now made to Equation (5). This equation is design in light of this parameter, ALT/AAG could be used for prevent a thick lens element in the optical imaging lens effectively. Therefore, the value of ALT/AAG is preferably less than or equal to 3.5 to satisfy Equation (5), and more preferably, the value of ALT/AAG is suggested for a lower limit, such as 1.2.

Reference is now made to Equation (6). As mentioned above, a large AG23 is desirable, and this makes a small T5/AG23 desirable. Therefore, the value of T5/AG23 is preferably less than or equal to 2.0 to satisfy Equation (6), and more preferably, the value of T5/AG23 is suggested for a lower limit, such as 0.7.

Reference is now made to Equations (7) and (8). As mentioned above, a large AG23 is desirable, and this makes a small T4/AG23 and ALT/AG23 desirable. Therefore, the value of T4/AG23 is preferably less than or equal to 4.0 to satisfy Equation (7), and more preferably, the value of T4/AG23 is suggested for a lower limit, such as 0.4; the value of ALT/AG23 is preferably less than or equal to 10.0 to satisfy Equation (8), and more preferably, the value of ALT/AG23 is suggested for a lower limit, such as 3.0.

Reference is now made to Equation (9). Although each air gap is shortened for facilitating the shortening of the length of the optical imaging lens, the one between the first and second lens element is required for a certain value for receiving the aperture stop, and the one between the second and third lens element is also required for a certain value. This makes the air gaps AG34 and AG45 have more potential for shortening and a big AAG/(AG34+AG45) is desirable. Therefore, the value of AAG/(AG34+AG45) is preferably larger than or equal to 4.5 to satisfy Equation (9), and more preferably, the value of AAG/(AG34+AG45) is suggested for an upper limit, such as 11.0.

Reference is now made to Equations (10) and (11). As mentioned before, AG12 is required for a certain value for receiving the aperture stop. Small values of T1 and T4 are desirable for shortening the length of the optical imaging lens, and this makes small values of T1/AG12 and T4/AG12 desirable. Therefore, the value of T1/AG12 is preferably smaller than or equal to 2.8 to satisfy Equation (10), and more preferably, the value of T1/AG12 is suggested for a lower limit, such as 0.4; the value of T4/AG12 is preferably smaller than or equal to 2.0 to satisfy Equation (10), and more preferably, the value of T4/AG12 is suggested for a lower limit, such as 0.4.

Reference is now made to Equation (12). If the value of ALT/T3 is within 3.56.0 to satisfy Equation (12), the configuration for the values of T3 could be better.

Reference is now made to Equation (13). The thickness of the fifth lens element is less likely to be shortened since the area for passing the light in the fifth lens element is larger than that of the fourth lens element. This makes a big T5/T4 desirable. Therefore, the value of T5/T4 is preferably larger than or equal to 0.8 to satisfy Equation (13), and more preferably, the value of T5/T4 is suggested for an upper limit, such as 3.0.

Reference is now made to Equation (14). Considering of the difficulty faced in the manufacturing process which may occur when AAG is small, the value of AAG/T4 is preferable larger than or equal to 1.7 to satisfy Equation (14), and more preferably, the value of AAG/T4 is suggested for an upper limit, such as 5.0.

When implementing example embodiments, more details about the convex or concave surface structure and/or the refracting power may be incorporated for one specific lens element or broadly for plural lens elements to enhance the control for the system performance and/or resolution, as illustrated in the following embodiments. For example, the object-side surface of the second lens element may further comprise a concave portion in a vicinity of a periphery of the second lens element, the object-side surface of the third lens element may further comprise a concave portion in a vicinity of the optical axis, the image-side surface of said third lens element comprises a convex portion in a vicinity of the optical axis, the object-side surface of the fourth lens element may further comprise a convex portion in a vicinity of the optical axis and/or the fifth lens element may have positive refracting power, etc. It is noted that the details could be incorporated in example embodiments if no inconsistency occurs.

Several exemplary embodiments and associated optical data will now be provided for illustrating example embodiments of optical imaging lens with good optical characters and a shortened length. Reference is now made to FIGS. 2-5. FIG. 2 illustrates an example cross-sectional view of an optical imaging lens 1 having five lens elements of the optical imaging lens according to a first example embodiment. FIG. 3 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 1 according to an example embodiment. FIG. 4 illustrates an example table of optical data of each lens element of the optical imaging lens 1 according to an example embodiment. FIG. 5 depicts an example table of aspherical data of the optical imaging lens 1 according to an example embodiment.

As shown in FIG. 2, the optical imaging lens 1 of the present embodiment comprises, in order from an object side A1 to an image side A2 along an optical axis, a first lens element 110, an aperture stop 100, a second lens element 120, a third lens element 130, a fourth lens element 140 and a fifth lens element 150. A filtering unit 160 and an image plane 170 of an image sensor are positioned at the image side A2 of the optical lens 1. Each of the first, second, third, fourth, fifth lens elements 110, 120, 130, 140, 150 and the filtering unit 160 comprises an object-side surface 111/121/131/141/151/161 facing toward the object side A1 and an image-side surface 112/122/132/142/152/162 facing toward the image side A2. The example embodiment of the filtering unit 160 illustrated is an IR cut filter (infrared cut filter) positioned between the fifth lens element 150 and an image plane 170. The filtering unit 160 selectively absorbs light with specific wavelength from the light passing optical imaging lens 1. For example, IR light is absorbed, and this will prohibit the IR light which is not seen by human eyes from producing an image on the image plane 170.

Exemplary embodiments of each lens element of the optical imaging lens 1 which may be constructed by plastic material will now be described with reference to the drawings.

An example embodiment of the first lens element 110 may have positive refracting power. The object-side surface 111 is a convex surface, and the image-side surface 112 is a concave surface.

An example embodiment of the second lens element 120 may have positive refracting power. The object-side surface 121 comprises a convex portion 1211 in a vicinity of the optical axis and a concave portion 1212 in a vicinity of a periphery of the second lens element 120. The image-side surface 122 is a convex surface.

An example embodiment of the third lens element 130 may have positive refracting power. The object-side surface 131 is a concave surface comprising a concave portion 1311 in a vicinity of the optical axis. The image-side surface 132 is a convex surface comprising a convex portion 1321 in a vicinity of the optical axis.

An example embodiment of the fourth lens element 140 may have negative refracting power. The object-side surface 141 comprises a convex portion 1411 in a vicinity of the optical axis and a concave portion 1412 in a vicinity of a periphery of the fourth lens element 140. The image-side surface 142 comprises a concave portion 1421 in a vicinity of the optical axis and a convex portion 1422 in a vicinity of a periphery of the fourth lens element 140.

An example embodiment of the fifth lens element 150 may have positive refracting power. The object-side surface 151 comprises a convex portion 1511 in a vicinity of the optical axis and a concave portion 1512 in a vicinity of a periphery of the fifth lens element 150. The image-side surface 152 comprises a concave portion 1521 in a vicinity of the optical axis and a convex portion 1522 in a vicinity of a periphery of the fifth lens element 150.

In example embodiments, air gaps exist between the lens elements 110, 120, 130, 140, 150, the filtering unit 160 and the image plane 170 of the image sensor. For example, FIG. 1 illustrates the air gap d1 existing between the first lens element 110 and the second lens element 120, the air gap d2 existing between the second lens element 120 and the third lens element 130, the air gap d3 existing between the third lens element 130 and the fourth lens element 140, the air gap d4 existing between the fourth lens element 140 and the fifth lens element 150, the air gap d5 existing between the fifth lens element 150 and the filtering unit 160, and the air gap d6 existing between the filtering unit 160 and the image plane 170 of the image sensor. However, in other embodiments, any of the aforesaid air gaps may or may not exist. For example, the profiles of opposite surfaces of any two adjacent lens elements may correspond to each other, and in such situation, the air gap may not exist. The air gap dl between the first lens element 110 and the second lens element 120 is denoted by AG12, the air gap d2 between the second lens element 120 and the third lens element 130 is denoted by AG23, the air gap d3 between the third lens element 130 and the fourth lens element 140 is denoted by AG34, and the air gap d4 between the fourth lens element 140, the fifth lens element 150 is denoted by AG45 and the sum of d1, d2, d3 and d4 is denoted by AAG.

FIG. 4 depicts the optical characters of each lens elements in the optical imaging lens 1 of the present embodiment, wherein the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 are:

-   -   ALT=2.279 (mm);     -   AAG=0.732 (mm);     -   T2/AG23=2.471;     -   T4/T3=1.757;     -   ALT/AAG=2.116;     -   T2/T3=2.224;     -   T5/AG23=1.074;     -   T2/AG12=1.846;     -   T4/AG23=1.953;     -   ALT/AG23=8.397;     -   AAG/(AG34+AG45)=7.561;     -   T1/AG12=1.335;     -   T4/AG12=1.459;     -   ALT/T3=7.555;     -   T5/T4=0.550;     -   AAG/T4=1.380.

The distance from the object-side surface 111 of the first lens element 110 to the image plane 170 along the optical axis is 4.034 mm, and the length of the optical imaging lens 1 is shortened.

Please note that the HFOV of the optical imaging lens 1 is 46.912 degrees and this is capable to provide a good image quality.

The aspherical surfaces, including the object-side surface 111 and the image-side surface 112 of the first lens element 110, the object-side surface 121 and the image-side surface 122 of the second lens element 120, the object-side surface 131 and the image-side surface 132 of the third lens element 130, the object-side surface 141 and the image-side surface 142 of the fourth lens element 140, and the object-side surface 151 and the image-side surface 152 of the fifth lens element 150 are all defined by the following aspherical formula:

${Z(Y)} = {{\frac{Y^{2}}{R}/\left( {1 + \sqrt{1 - {\left( {1 + K} \right)\frac{Y^{2}}{R^{2}}}}} \right)} + {\sum\limits_{i = 1}^{n}{a_{i} \times Y^{i}}}}$

-   -   wherein,     -   R represents the radius of curvature of the surface of the lens         element;     -   Z represents the depth of the aspherical surface (the         perpendicular distance between the point of the aspherical         surface at a distance Y from the optical axis and the tangent         plane of the vertex on the optical axis of the aspherical         surface);     -   Y represents the perpendicular distance between the point of the         aspherical surface and the optical axis;     -   K represents a conic constant;     -   a_(i) represents an aspherical coefficient of i^(th) level.

The values of each aspherical parameter are shown in FIG. 5.

As illustrated in FIG. 3, longitudinal spherical aberration (a), the curves of different wavelengths are closed to each other. This represents off-axis light with respect to these wavelengths is well focused. From the longitudinal deviation of each curve shown therein, the offset of the off-axis light relative to the image point is within ±0.02 mm. Therefore, the present embodiment improves the longitudinal spherical aberration with respect to different wavelengths.

Please refer to FIG. 3, astigmatism aberration in the sagittal direction (b) and astigmatism aberration in the tangential direction (c). The focus variation with respect to the three wavelengths in the whole field falls within ±0.1 mm. This reflects the optical imaging lens 1 of the present embodiment eliminates aberration effectively.

Please refer to FIG. 3, distortion aberration (d), which showing the variation of the distortion aberration is within ±2%. Such distortion aberration meets the requirement of acceptable image quality and shows the optical imaging lens 1 of the present embodiment could restrict the distortion aberration to raise the image quality even though the length of the optical imaging lens 1 is shortened to 4.034 mm with about 47 degrees in HFOV.

Therefore, the optical imaging lens 1 of the present embodiment shows great characteristics in the longitudinal spherical aberration, astigmatism in the sagittal direction, astigmatism in the tangential direction, and distortion aberration. According to above illustration, the optical imaging lens 1 of the example embodiment indeed achieves great optical performance and the length of the optical imaging lens 1 is effectively shortened.

Reference is now made to FIGS. 6-9. FIG. 6 illustrates an example cross-sectional view of an optical imaging lens 2 having five lens elements of the optical imaging lens according to a second example embodiment. FIG. 7 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 2 according to the second example embodiment. FIG. 8 shows an example table of optical data of each lens element of the optical imaging lens 2 according to the second example embodiment. FIG. 9 shows an example table of aspherical data of the optical imaging lens 2 according to the second example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 2, for example, reference number 231 for labeling the object-side surface of the third lens element 230, reference number 232 for labeling the image-side surface of the third lens element 230, etc.

As shown in FIG. 6, the optical imaging lens 2 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises a first lens element 210, an aperture stop 200, a second lens element 220, a third lens element 230, a fourth lens element 240 and a fifth lens element 250.

The differences between the second embodiment and the first embodiment are the radius of curvature and thickness of each lens element, the distance of each air gap and the configuration of the positive/negative refracting power of the first lens elements 210, but the configuration of the positive/negative refracting power of the second, third, fourth and fifth lens elements 220, 230, 240, 250 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 211, 221, 231, 241, 251 facing to the object side A1 and the image-side surfaces 212, 222, 232, 242, 252 facing to the image side A2, are similar to those in the first embodiment. Specifically, the first lens element 210 has negative refracting power. Please refer to FIG. 8 for the optical characteristics of each lens elements in the optical imaging lens 2 of the present embodiment, wherein the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 are:

-   -   ALT=2.312 (mm);     -   AAG=0.696 (mm);     -   T2/AG23=2.202;     -   T4/T3=0.430;     -   ALT/AAG=3.324;     -   T2/T3=0.911;     -   T5/AG23=1.977;     -   T2/AG12=1.693;     -   T4/AG23=1.039;     -   ALT/AG23=9.242;     -   AAG/(AG34+AG45)=5.796;     -   T1/AG12=1.234;     -   T4/AG12=0.799;     -   ALT/T3=3.823;     -   T5/T4=1.903;     -   AAG/T4=2.675.

The distance from the object-side surface 211 of the first lens element 210 to the image plane 270 along the optical axis is 4.063 mm and the length of the optical imaging lens 2 is shortened. Meanwhile, the HFOV of the optical imaging lens 2 reaches 47.498 degrees.

As shown in FIG. 7, the optical imaging lens 2 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 2 is effectively shortened.

Reference is now made to FIGS. 10-13. FIG. 10 illustrates an example cross-sectional view of an optical imaging lens 3 having five lens elements of the optical imaging lens according to a third example embodiment. FIG. 11 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 3 according to the third example embodiment. FIG. 12 shows an example table of optical data of each lens element of the optical imaging lens 3 according to the third example embodiment. FIG. 13 shows an example table of aspherical data of the optical imaging lens 3 according to the third example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 3, for example, reference number 331 for labeling the object-side surface of the third lens element 330, reference number 332 for labeling the image-side surface of the third lens element 330, etc.

As shown in FIG. 10, the optical imaging lens 3 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises a first lens element 310, an aperture stop 300, a second lens element 320, a third lens element 330, a fourth lens element 340 and a fifth lens element 350.

The differences between the third embodiment and the second embodiment are the radius of curvature and thickness of each lens element and the distance of each air gap, but the configuration of the positive/negative refracting power of the first, second, third, fourth and fifth lens elements 310, 320, 330, 340, 350 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 311, 321, 331, 341, 351 facing to the object side A1 and the image-side surfaces 312, 322, 332, 342, 352 facing to the image side A2, are similar to those in the second embodiment. Please refer to FIG. 12 for the optical characteristics of each lens elements in the optical imaging lens 3 of the present embodiment, wherein the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 are:

-   -   ALT=2.328 (mm);     -   AAG=0.699 (mm);     -   T2/AG23=2.008;     -   T4/T3=0.356;     -   ALT/AAG=3.331;     -   T2/T3=0.654;     -   T5/AG23=2.010;     -   T2/AG12=1.254;     -   T4/AG23=1.094;     -   ALT/AG23=9.964;     -   AAG/(AG34+AG45)=7.672;     -   T1/AG12=1.111;     -   T4/AG12=0.683;     -   ALT/T3=3.243;     -   T5/T4=1.837;     -   AAG/T4=2.734.

The distance from the object-side surface 311 of the first lens element 310 to the image plane 370 along the optical axis is 4.083 mm and the length of the optical imaging lens 3 is shortened. Meanwhile, the HFOV of the optical imaging lens 3 reaches 48.038 degrees.

As shown in FIG. 11, the optical imaging lens 3 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 3 is effectively shortened

Reference is now made to FIGS. 14-17. FIG. 14 illustrates an example cross-sectional view of an optical imaging lens 4 having five lens elements of the optical imaging lens according to a fourth example embodiment. FIG. 15 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 4 according to the fourth embodiment. FIG. 16 shows an example table of optical data of each lens element of the optical imaging lens 4 according to the fourth example embodiment. FIG. 17 shows an example table of aspherical data of the optical imaging lens 4 according to the fourth example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 4, for example, reference number 431 for labeling the object-side surface of the third lens element 430, reference number 432 for labeling the image-side surface of the third lens element 430, etc.

As shown in FIG. 14, the optical imaging lens 4 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises a first lens element 410, an aperture stop 400, a second lens element 420, a third lens element 430, a fourth lens element 440 and a fifth lens element 450.

The differences between the fourth embodiment and the first embodiment are the radius of curvature and thickness of each lens element and the distance of each air gap, but the configuration of the positive/negative refracting power of the first, second, third, fourth and fifth lens elements 410, 420, 430, 440, 450 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 411, 421, 431, 441, 451 facing to the object side A1 and the image-side surfaces 412, 422, 432, 442, 452 facing to the image side A2, are similar to those in the first embodiment. Please refer to FIG. 16 for the optical characteristics of each lens elements in the optical imaging lens 4 of the present embodiment, wherein the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 are:

-   -   ALT=2.369 (mm);     -   AAG=0.501 (mm);     -   T2/AG23=2.881;     -   T4/T3=1.369;     -   ALT/AAG=4.724;     -   T2/T3=2.298;     -   T5/AG23=1.142;     -   T2/AG12=5.026;     -   T4/AG23=1.716;     -   ALT/AG23=9.011;     -   AAG/(AG34+AG45)=5.702;     -   T1/AG12=3.522;     -   T4/AG12=2.994;     -   ALT/T3=7.189;     -   T5/T4=0.666;     -   AAG/T4=1.112.

The distance from the object-side surface 411 of the first lens element 410 to the image plane 470 along the optical axis is 3.860 mm and the length of the optical imaging lens 4 is shortened. Meanwhile, the HFOV of the optical imaging lens 4 reaches 46.869 degrees.

As shown in FIG. 15, the optical imaging lens 4 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 4 is effectively shortened.

Reference is now made to FIGS. 18-21. FIG. 18 illustrates an example cross-sectional view of an optical imaging lens 5 having five lens elements of the optical imaging lens according to a fifth example embodiment. FIG. 19 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 5 according to the fifth embodiment. FIG. 20 shows an example table of optical data of each lens element of the optical imaging lens 5 according to the fifth example embodiment. FIG. 21 shows an example table of aspherical data of the optical imaging lens 5 according to the fifth example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 5, for example, reference number 531 for labeling the object-side surface of the third lens element 530, reference number 532 for labeling the image-side surface of the third lens element 530, etc.

As shown in FIG. 18, the optical imaging lens 5 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises a first lens element 510, an aperture stop 500, a second lens element 520, a third lens element 530, a fourth lens element 540 and a fifth lens element 550.

The differences between the fifth embodiment and the second embodiment are the radius of curvature and thickness of each lens element and the distance of each air gap, but the configuration of the positive/negative refracting power of the first, second, third, fourth and fifth lens elements 510, 520, 530, 540, 550 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 511, 521, 531, 541, 551 facing to the object side A1 and the image-side surfaces 512, 522, 532, 542, 552 facing to the image side A2, are similar to those in the second embodiment. Please refer to FIG. 20 for the optical characteristics of each lens elements in the optical imaging lens 5 of the present embodiment, wherein the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 are:

-   -   ALT=2.215 (mm);     -   AAG=0.815 (mm);     -   T2/AG23=1.896;     -   T4/T3=0.497;     -   ALT/AAG=2.718;     -   T2/T3=1.084;     -   T5/AG23=1.449;     -   T2/AG12=1.647;     -   T4/AG23=0.869;     -   ALT/AG23=7.424;     -   AAG/(AG34+AG45)=4.710;     -   T1/AG12=1.268;     -   T4/AG12=0.755;     -   ALT/T3=4.243;     -   T5/T4=1.667;     -   AAG/T4=3.143.

The distance from the object-side surface 511 of the first lens element 510 to the image plane 570 along the optical axis is 4.085 mm and the length of the optical imaging lens 5 is shortened. Meanwhile, the HFOV of the optical imaging lens 5 reaches 46.952 degrees.

As shown in FIG. 19, the optical imaging lens 5 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 5 is effectively shortened.

Reference is now made to FIGS. 22-25. FIG. 22 illustrates an example cross-sectional view of an optical imaging lens 6 having five lens elements of the optical imaging lens according to a sixth example embodiment. FIG. 23 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 6 according to the sixth embodiment. FIG. 24 shows an example table of optical data of each lens element of the optical imaging lens 6 according to the sixth example embodiment. FIG. 25 shows an example table of aspherical data of the optical imaging lens 6 according to the sixth example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 6, for example, reference number 631 for labeling the object-side surface of the third lens element 630, reference number 632 for labeling the image-side surface of the third lens element 630, etc.

As shown in FIG. 22, the optical imaging lens 6 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises a first lens element 610, an aperture stop 600, a second lens element 620, a third lens element 630, a fourth lens element 640 and a fifth lens element 650.

The differences between the sixth embodiment and the second embodiment are the radius of curvature and thickness of each lens element, the distance of each air gap and the concave/convex shape of surfaces 621, 641, but the configuration of the positive/negative refracting power of the first, second, third, fourth and fifth lens elements 610, 620, 630, 640, 650 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 611, 631, 651 facing to the object side A1 and the image-side surfaces 612, 622, 632, 642, 652 facing to the image side A2, are similar to those in the second embodiment. Specifically, the object-side surface 621 of the second lens element 620 is a convex surface, and the object-side surface 641 of the fourth lens element 640 comprises a concave portion 6411 in a vicinity of the optical axis. Please refer to FIG. 24 for the optical characteristics of each lens elements in the optical imaging lens 6 of the present embodiment, wherein the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 are:

-   -   ALT=2.058 (mm);     -   AAG=1.239 (mm);     -   T2/AG23=0.906;     -   T4/T3=0.428;     -   ALT/AAG=1.661;     -   T2/T3=0.728;     -   T5/AG23=0.890;     -   T2/AG12=0.707;     -   T4/AG23=0.532;     -   ALT/AG23=4.215;     -   AAG/(AG34+AG45)=9.913;     -   T1/AG12=0.500;     -   T4/AG12=0.415;     -   ALT/T3=3.386;     -   T5/T4=1.672;     -   AAG/T4=4.766.

The distance from the object-side surface 611 of the first lens element 610 to the image plane 670 along the optical axis is 4.450 mm and the length of the optical imaging lens 6 is shortened. Meanwhile, the HFOV of the optical imaging lens 6 reaches 45.964 degrees.

As shown in FIG. 23, the optical imaging lens 6 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 6 is effectively shortened.

Reference is now made to FIGS. 26-29. FIG. 26 illustrates an example cross-sectional view of an optical imaging lens 7 having five lens elements of the optical imaging lens according to a seventh example embodiment. FIG. 27 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 7 according to the seventh embodiment. FIG. 28 shows an example table of optical data of each lens element of the optical imaging lens 7 according to the seventh example embodiment. FIG. 29 shows an example table of aspherical data of the optical imaging lens 7 according to the seventh example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 7, for example, reference number 731 for labeling the object-side surface of the third lens element 730, reference number 732 for labeling the image-side surface of the third lens element 730, etc.

As shown in FIG. 26, the optical imaging lens 7 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises a first lens element 710, an aperture stop 700, a second lens element 720, a third lens element 730, a fourth lens element 740 and a fifth lens element 750.

The differences between the seventh embodiment and the second embodiment are the radius of curvature and thickness of each lens element, the distance of each air gap and the configuration of the concave/convex shape of surfaces 721, 731, but the configuration of the positive/negative refracting power of the first, second, third, fourth and fifth lens elements 710, 720, 730, 740, 750 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 711, 741, 751 facing to the object side A1 and the image-side surfaces 712, 722, 732, 742, 752 facing to the image side A2, are similar to those in the second embodiment. Specifically, the object-side surface 721 of the second lens element 720 is a convex surface comprising a convex portion 7211 in a vicinity of a periphery of the second lens element 720, and the object-side surface 731 of the third lens element 730 comprises a convex portion 7311 in a vicinity of a periphery of the third lens element 730. Please refer to FIG. 28 for the optical characteristics of each lens elements in the optical imaging lens 7 of the present embodiment, wherein the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 are:

-   -   ALT=2.367 (mm);     -   AAG=0.841 (mm);     -   T2/AG23=1.014;     -   T4/T3=0.445;     -   ALT/AAG=2.815;     -   T2/T3=0.799;     -   T5/AG23=0.818;     -   T2/AG12=1.821;     -   T4/AG23=0.566;     -   ALT/AG23=5.149;     -   AAG/(AG34+AG45)=6.727;     -   T1/AG12=2.660;     -   T4/AG12=1.015;     -   ALT/T3=4.056;     -   T5/T4=1.446;     -   AAG/T4=3.234.

The distance from the object-side surface 711 of the first lens element 710 to the image plane 770 along the optical axis is 4.309 mm and the length of the optical imaging lens 7 is shortened. Meanwhile, the HFOV of the optical imaging lens 7 reaches 45.905 degrees.

As shown in FIG. 27, the optical imaging lens 7 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 7 is effectively shortened.

Reference is now made to FIGS. 30-33. FIG. 30 illustrates an example cross-sectional view of an optical imaging lens 8 having five lens elements of the optical imaging lens according to a eighth example embodiment. FIG. 31 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 8 according to the eighth embodiment. FIG. 32 shows an example table of optical data of each lens element of the optical imaging lens 8 according to the eighth example embodiment. FIG. 33 shows an example table of aspherical data of the optical imaging lens 8 according to the eighth example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 8, for example, reference number 831 for labeling the object-side surface of the third lens element 830, reference number 832 for labeling the image-side surface of the third lens element 830, etc.

As shown in FIG. 30, the optical imaging lens 8 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises a first lens element 810, an aperture stop 800, a second lens element 820, a third lens element 830, a fourth lens element 840 and a fifth lens element 850.

The differences between the eighth embodiment and the first embodiment are the radius of curvature and thickness of each lens element, the distance of each air gap and the configuration of the concave/convex shape of surfaces 821, 832, but the configuration of the positive/negative refracting power of the first, second, third, fourth and fifth lens elements 810, 820, 830, 840, 850 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 811, 831, 841, 851 facing to the object side A1 and the image-side surfaces 812, 822, 842, 852 facing to the image side A2, are similar to those in the first embodiment. Specifically, the object-side surface 821 of the second lens element 820 is a concave surface comprising a convex portion 8211 in a vicinity of the optical axis, and the image-side surface 832 of the third lens element 830 comprises a concave portion 8321 in a vicinity of a periphery of the third lens element 830. Please refer to FIG. 32 for the optical characteristics of each lens elements in the optical imaging lens 8 of the present embodiment, wherein the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 are:

-   -   ALT=2.222 (mm); AAG=0.728 (mm);     -   T2/AG23=1.598; T4/T3=0.852;     -   ALT/AAG=3.053;     -   T2/T3=1.225;     -   T5/AG23=0.823;     -   T2/AG12=2.547;     -   T4/AG23=1.112;     -   ALT/AG23=5.978;     -   AAG/(AG34+AG45)=5.925;     -   T1/AG12=1.817;     -   T4/AG12=1.772;     -   ALT/T3=4.583;     -   T5/T4=0.741;     -   AAG/T4=1.761.

The distance from the object-side surface 811 of the first lens element 810 to the image plane 870 along the optical axis is 4.009 mm and the length of the optical imaging lens 8 is shortened. Meanwhile, the HFOV of the optical imaging lens 8 reaches 45.919 degrees.

As shown in FIG. 31, the optical imaging lens 8 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 8 is effectively shortened.

Reference is now made to FIGS. 34-37. FIG. 34 illustrates an example cross-sectional view of an optical imaging lens 9 having five lens elements of the optical imaging lens according to a ninth example embodiment. FIG. 35 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 9 according to the ninth embodiment. FIG. 36 shows an example table of optical data of each lens element of the optical imaging lens 9 according to the ninth example embodiment. FIG. 37 shows an example table of aspherical data of the optical imaging lens 9 according to the ninth example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 9, for example, reference number 931 for labeling the object-side surface of the third lens element 930, reference number 932 for labeling the image-side surface of the third lens element 930, etc.

As shown in FIG. 34, the optical imaging lens 9 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises a first lens element 910, an aperture stop 900, a second lens element 920, a third lens element 930, a fourth lens element 940 and a fifth lens element 950.

The differences between the ninth embodiment and the eighth embodiment are the radius of curvature and thickness of each lens element, the distance of each air gap, the configuration of the positive/negative refracting power of the first lens elements 910 and the configuration of the concave/convex shape of surface 951, but the configuration of the positive/negative refracting power of the first, second, third, fourth and fifth lens elements 920, 930, 940, 950 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 911, 921, 931, 941 facing to the object side A1 and the image-side surfaces 912, 922, 932, 942, 952 facing to the image side A2, are similar to those in the eighth embodiment. Specifically, the first lens element 910 has negative refracting power, and the object-side surface 951 of the fifth lens element 950 comprises a convex portion 9511 in a vicinity of the optical axis, a convex portion 9512 in a vicinity of a periphery of the fifth lens element 950 and a concave portion 9513 between the vicinity of the optical axis and the vicinity of the periphery of the fifth lens element 950. Please refer to FIG. 36 for the optical characteristics of each lens elements in the optical imaging lens 9 of the present embodiment, wherein the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 are:

-   -   ALT=2.245 (mm);     -   AAG=0.878 (mm);     -   T2/AG23=1.241;     -   T4/T3=0.622;     -   ALT/AAG=2.557;     -   T2/T3=1.196;     -   T5/AG23=1.651;     -   T2/AG12=1.243;     -   T4/AG23=0.645;     -   ALT/AG23=5.809;     -   AAG/(AG34+AG45)=8.302;     -   T1/AG12=1.237;     -   T4/AG12=0.646;     -   ALT/T3=5.600;     -   T5/T4=2.560;     -   AAG/T4=3.523.

The distance from the object-side surface 911 of the first lens element 910 to the image plane 970 along the optical axis is 4.130 mm and the length of the optical imaging lens 9 is shortened. Meanwhile, the HFOV of the optical imaging lens 9 reaches 47.605 degrees.

As shown in FIG. 37, the optical imaging lens 9 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 9 is effectively shortened.

Reference is now made to FIGS. 38-41. FIG. 38 illustrates an example cross-sectional view of an optical imaging lens 10 having five lens elements of the optical imaging lens according to a tenth example embodiment. FIG. 39 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 10 according to the tenth embodiment. FIG. 40 shows an example table of optical data of each lens element of the optical imaging lens 10 according to the tenth example embodiment. FIG. 41 shows an example table of aspherical data of the optical imaging lens 10 according to the tenth example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 10, for example, reference number 1031 for labeling the object-side surface of the third lens element 1030, reference number 1032 for labeling the image-side surface of the third lens element 1030, etc.

As shown in FIG. 38, the optical imaging lens 10 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises a first lens element 1010, an aperture stop 1000, a second lens element 1020, a third lens element 1030, a fourth lens element 1040 and a fifth lens element 1050.

The differences between the tenth embodiment and the first embodiment are the radius of curvature and thickness of each lens element and the distance of each air gap, but the configuration of the positive/negative refracting power of the first, second, third, fourth and fifth lens elements 1010, 1020, 1030, 1040, 1050 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 1011, 1021, 1031, 1041, 1051 facing to the object side A1 and the image-side surfaces 1012, 1022, 1032, 1042, 1052 facing to the image side A2, are similar to those in the first embodiment. Please refer to FIG. 40 for the optical characteristics of each lens elements in the optical imaging lens 10 of the present embodiment, wherein the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 are:

-   -   ALT=2.374 (mm);     -   AAG=0.704 (mm);     -   T2/AG23=2.338;     -   T4/T3=1.975;     -   ALT/AAG=3.371;     -   T2/T3=1.219;     -   T5/AG23=0.389;     -   T2/AG12=1.192;     -   T4/AG23=3.787;     -   ALT/AG23=11.305;     -   AAG/(AG34+AG45)=8.546;     -   T1/AG12=0.954;     -   T4/AG12=1.931;     -   ALT/T3=5.894;     -   T5/T4=0.367;     -   AAG/T4=0.886.

The distance from the object-side surface 1011 of the first lens element 1010 to the image plane 1070 along the optical axis is 4.051 mm and the length of the optical imaging lens 10 is shortened. Meanwhile, the HFOV of the optical imaging lens 10 reaches 46.898 degrees.

As shown in FIG. 39, the optical imaging lens 10 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 10 is effectively shortened.

Reference is now made to FIGS. 42-45. FIG. 42 illustrates an example cross-sectional view of an optical imaging lens 11 having five lens elements of the optical imaging lens according to a eleventh example embodiment. FIG. 43 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 11 according to the eleventh embodiment. FIG. 44 shows an example table of optical data of each lens element of the optical imaging lens 11 according to the eleventh example embodiment. FIG. 45 shows an example table of aspherical data of the optical imaging lens 11 according to the eleventh example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 11, for example, reference number 1131 for labeling the object-side surface of the third lens element 1130, reference number 1132 for labeling the image-side surface of the third lens element 1130, etc.

As shown in FIG. 42, the optical imaging lens 11 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises a first lens element 1110, an aperture stop 1100, a second lens element 1120, a third lens element 1130, a fourth lens element 1140 and a fifth lens element 1150.

The differences between the eleventh embodiment and the second embodiment are the radius of curvature and thickness of each lens element and the distance of each air gap, but the configuration of the positive/negative refracting power of the first, second, third, fourth and fifth lens elements 1110, 1120, 1130, 1140, 1150 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 1111, 1121, 1131, 1141, 1151 facing to the object side A1 and the image-side surfaces 1112, 1122, 1132, 1142, 1152 facing to the image side A2, are similar to those in the second embodiment. Please refer to FIG. 44 for the optical characteristics of each lens elements in the optical imaging lens 11 of the present embodiment, wherein the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 are:

-   -   ALT=2.222 (mm);     -   AAG=0.792 (mm);     -   T2/AG23=2.107;     -   T4/T3=0.963;     -   ALT/AAG=2.806;     -   T2/T3=0.992;     -   T5/AG23=1.891;     -   T2/AG12=1.079;     -   T4/AG23=2.046;     -   ALT/AG23=9.866;     -   AAG/(AG34+AG45)=6.227;     -   T1/AG12=0.870;     -   T4/AG12=1.048;     -   ALT/T3=4.645;     -   T5/T4=0.924;     -   AAG/T4=1.719.

The distance from the object-side surface 1111 of the first lens element 1110 to the image plane 1170 along the optical axis is 4.033 mm and the length of the optical imaging lens 11 is shortened. Meanwhile, the HFOV of the optical imaging lens 11 reaches 47.634 degrees.

As shown in FIG. 43, the optical imaging lens 11 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 11 is effectively shortened.

Please refer to FIG. 46, which shows the values of ALT, AAG, T2/AG23, T4/T3, ALT/AAG, T2/T3, T5/AG23, T2/AG12, T4/AG23, ALT/AG23, AAG/(AG34+AG45), T1/AG12, T4/AG12, ALT/T3, T5/T4 and AAG/T4 of all eleventh embodiments, and it is clear that the optical imaging lens of the present invention satisfy the Equations (1), (2), (3), (4), (5), (6), (7), (8), (9), (10)/(10′), (11), (12), (13) and/or (14).

Reference is now made to FIG. 47, which illustrates an example structural view of a first embodiment of mobile device 20 applying an aforesaid optical imaging lens. The mobile device 20 comprises a housing 21 and a photography module 22 positioned in the housing 21. Examples of the mobile device 20 may be, but are not limited to, a mobile phone, a camera, a tablet computer, a personal digital assistant (PDA), etc.

As shown in FIG. 47, the photography module 22 may comprise an aforesaid optical imaging lens with five lens elements, for example the optical imaging lens 1 of the first embodiment, a lens barrel 23 for positioning the optical imaging lens 1, a module housing unit 24 for positioning the lens barrel 23, a substrate 172 for positioning the module housing unit 24, and an image sensor 171 which is positioned at an image side of the optical imaging lens 1. The image plane 170 is formed on the image sensor 171.

In some other example embodiments, the structure of the filtering unit 160 may be omitted. In some example embodiments, the housing 21, the lens barrel 23, and/or the module housing unit 24 may be integrated into a single component or assembled by multiple components. In some example embodiments, the image sensor 171 used in the present embodiment is directly attached to a substrate 172 in the form of a chip on board (COB) package, and such package is different from traditional chip scale packages (CSP) since COB package does not require a cover glass before the image sensor 171 in the optical imaging lens 1. Aforesaid exemplary embodiments are not limited to this package type and could be selectively incorporated in other described embodiments.

The five lens elements 110, 120, 130, 140, 150 are positioned in the lens barrel 23 in the way of separated by an air gap between any two adjacent lens elements.

The module housing unit 24 comprises a lens backseat 2401 for positioning the lens barrel 23 and an image sensor base 2406 positioned between the lens backseat 2401 and the image sensor 171. The lens barrel 23 and the lens backseat 2401 are positioned along a same axis I-I′, and the lens backseat 2401 is close to the outside of the lens barrel 23. The image sensor base 2406 is exemplarily close to the lens backseat 2401 here. The image sensor base 2406 could be optionally omitted in some other embodiments of the present invention.

Because the length of the optical imaging lens 1 is merely 4.034 mm, the size of the mobile device 20 may be quite small. Therefore, the embodiments described herein meet the market demand for smaller sized product designs.

Reference is now made to FIG. 48, which shows another structural view of a second embodiment of mobile device 20′ applying the aforesaid optical imaging lens 1. One difference between the mobile device 20′ and the mobile device 20 may be the lens backseat 2401 comprising a first seat unit 2402, a second seat unit 2403, a coil 2404 and a magnetic unit 2405. The first seat unit 2402 is close to the outside of the lens barrel 23, and positioned along an axis I-I′, and the second seat unit 2403 is around the outside of the first seat unit 2402 and positioned along with the axis I-I′. The coil 2404 is positioned between the first seat unit 2402 and the inside of the second seat unit 2403. The magnetic unit 2405 is positioned between the outside of the coil 2404 and the inside of the second seat unit 2403.

The lens barrel 23 and the optical imaging lens 1 positioned therein are driven by the first seat unit 2402 for moving along the axis I-I′. The rest structure of the mobile device 20′ is similar to the mobile device 20.

Similarly, because the length of the optical imaging lens 1, 4.034 mm, is shortened, the mobile device 20′ may be designed with a smaller size and meanwhile good optical performance is still provided. Therefore, the present embodiment meets the demand of small sized product design and the request of the market.

According to above illustration, it is clear that the mobile device and the optical imaging lens thereof in example embodiments, through controlling the detail structure and/or reflection power of the lens elements, the length of the optical imaging lens is effectively shortened and meanwhile good optical characters are still provided.

While various embodiments in accordance with the disclosed principles been described above, it should be understood that they are presented by way of example only, and are not limiting. Thus, the breadth and scope of exemplary embodiment(s) should not be limited by any of the above-described embodiments, but should be defined only in accordance with the claims and their equivalents issuing from this disclosure. Furthermore, the above advantages and features are provided in described embodiments, but shall not limit the application of such issued claims to processes and structures accomplishing any or all of the above advantages.

Additionally, the section headings herein are provided for consistency with the suggestions under 37 C.F.R. 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the invention(s) set out in any claims that may issue from this disclosure. Specifically, a description of a technology in the “Background” is not to be construed as an admission that technology is prior art to any invention(s) in this disclosure. Furthermore, any reference in this disclosure to “invention” in the singular should not be used to argue that there is only a single point of novelty in this disclosure. Multiple inventions may be set forth according to the limitations of the multiple claims issuing from this disclosure, and such claims accordingly define the invention(s), and their equivalents, that are protected thereby. In all instances, the scope of such claims shall be considered on their own merits in light of this disclosure, but should not be constrained by the headings herein. 

What is claimed is:
 1. An optical imaging lens, sequentially from an object side to an image side along an optical axis, comprising a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element, each of the first, second, third, fourth and fifth lens elements having an object-side surface facing toward the object side and allowing imaging rays to pass therethrough and an image-side surface facing toward the image side and allowing the imaging rays to pass therethrough, wherein: the object-side surface of the third lens element comprises a concave portion in a vicinity of a periphery of the third lens element; the image-side surface of the fourth lens element comprises a concave portion in a vicinity of the optical axis; and the optical imaging lens as a whole has only the five lens elements, wherein an effective focal length is EFL, a central thickness of the second lens element along the optical axis is T2, a central thickness of the third lens element along the optical axis is T3, a central thickness of the fourth lens element along the optical axis is T4, a central thickness of the fifth lens element along the optical axis is T5, an air gap between the fourth lens element and the fifth lens element along the optical axis is AG45, and EFL, T2, T3, T4, T5 and AG45 satisfy the equations: EFL/T5≤7.270, (T4+AG45)/T3≤2.080, and T2/T3≤1.200.
 2. The optical imaging lens according to claim 1, wherein a central thickness of the first lens element along the optical axis is T1, an air gap between the third lens element and the fourth lens element along the optical axis is AG34, and T1, AG34 and T5 satisfy the equation: (T1+AG34)/T5≤1.971.
 3. The optical imaging lens according to claim 1, wherein an air gap between the third lens element and the fourth lens element along the optical axis is AG34, and T3, AG34 and T5 satisfy the equation: (T3+AG34)/T5≤1.777.
 4. The optical imaging lens according to claim 1, wherein a sum of all four air gaps from the first lens element to the fifth lens element along the optical axis is AAG, and AAG and T5 satisfy the equation: AAG/T5≤3.100.
 5. The optical imaging lens according to claim 1, wherein a sum of thicknesses of all five lens elements along the optical axis is ALT, a central thickness of the first lens element along the optical axis is T1, and ALT and T1 satisfy the equation: ALT/T1≤6.574.
 6. The optical imaging lens according to claim 1, wherein a distance between the image-side surface of the fifth lens element and an image plane along the optical axis is BFL, and BFL and T3 satisfy the equation: BFL/T3≤3.393.
 7. The optical imaging lens according to claim 1, wherein an air gap between the second lens element and the third lens element along the optical axis is AG23, and T2 and AG23 satisfy the equation: T2/AG23≤2.500.
 8. An optical imaging lens, sequentially from an object side to an image side along an optical axis, comprising a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element, each of the first, second, third, fourth and fifth lens elements having an object-side surface facing toward the object side and allowing imaging rays to pass therethrough and an image-side surface facing toward the image side, and allowing the imaging rays to pass therethrough, wherein: the fourth lens element has negative refracting power; the image-side surface of the fourth lens element comprises a concave portion in a vicinity of the optical axis; and the optical imaging lens as a whole has only the five lens elements, wherein an effective focal length is EFL, a central thickness of the first lens element along the optical axis is T1, a central thickness of the fifth lens element along the optical axis is T5, an air gap between the third lens element and the fourth lens element along the optical axis is AG34, and EFL, T1, T5 and AG34 satisfy the equations: EFL/T5≤7.270, and (T1+AG34)/T5≤1.971.
 9. The optical imaging lens according to claim 8, wherein a central thickness of the third lens element along the optical axis is T3, a central thickness of the fourth lens element along the optical axis is T4, an air gap between the fourth lens element and the fifth lens element along the optical axis is AG45, and T3, T4 and AG45 satisfy the equation: (T4+AG45)/T3≤2.080.
 10. The optical imaging lens according to claim 8, wherein a central thickness of the third lens element along the optical axis is T3, a central thickness of the fourth lens element along the optical axis is T4, and T3 and T4 satisfy the equation: T4/T3≤1.800.
 11. The optical imaging lens according to claim 8, wherein a central thickness of the second lens element along the optical axis is T2, a central thickness of the third lens element along the optical axis is T3, and T2 and T3 satisfy the equation: T2/T3<1.200.
 12. The optical imaging lens according to claim 8, wherein a sum of thicknesses of all five lens elements along the optical axis is ALT, a sum of all four air gaps from the first lens element to the fifth lens element along the optical axis is AAG, and ALT and AAG satisfy the equation: ALT/AAG≤3.500.
 13. The optical imaging lens according to claim 8, wherein a central thickness of the second lens element along the optical axis is T2, an air gap between the first lens element and the second lens element along the optical axis is AG12, T2 and AG12 satisfy the equation: T2/AG12≤5.300.
 14. The optical imaging lens according to claim 8, wherein a central thickness of the fourth lens element along the optical axis is T4, an air gap between the second lens element and the third lens element along the optical axis is AG23, and T4 and AG23 satisfy the equation: T4/AG23≤4.000.
 15. An optical imaging lens, sequentially from an object side to an image side along an optical axis, comprising a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element, each of the first, second, third, fourth and fifth lens elements having an object-side surface facing toward the object side and allowing imaging rays to pass therethrough and an image-side surface facing toward the image side and allowing the imaging rays to pass therethrough, wherein: the third lens element has positive refracting power; the image-side surface of the fourth lens element comprises a concave portion in a vicinity of the optical axis; and the optical imaging lens as a whole has only the five lens elements, wherein an effective focal length is EFL, a central thickness of the first lens element along the optical axis is T1, a central thickness of the fifth lens element along the optical axis is T5, an air gap between the third lens element and the fourth lens element along the optical axis is AG34, and EFL, T1, T5 and AG34 satisfy the equations: EFL/T5≤7.270, and (T1+AG34)/T5≤1.971.
 16. The optical imaging lens according to claim 15, wherein an air gap between the second lens element and the third lens element along the optical axis is AG23, a sum of thicknesses of all five lens elements along the optical axis is ALT, and AG23 and ALT satisfy the equation: ALT/AG23≤10.000.
 17. The optical imaging lens according to claim 15, wherein a central thickness of the fourth lens element along the optical axis is T4, and T4 and T5 satisfy the equation: 0.800≤T5/T4.
 18. The optical imaging lens according to claim 15, wherein a central thickness of the fourth lens element along the optical axis is T4, a sum of all four air gaps from the first lens element to the fifth lens element along the optical axis is AAG, and T4 and AAG satisfy the equation: 1.700≤AAG/T4.
 19. The optical imaging lens according to claim 15, wherein a distance between the image-side surface of the fifth lens element and an image plane along the optical axis is BFL, and BFL and T1 satisfy the equation: 1.616≤BFL/T1≤3.682.
 20. The optical imaging lens according to claim 15, wherein a sum of all four air gaps from the first lens element to the fifth lens element along the optical axis is AAG, and AAG and T1 satisfy the equation: 0.945≤AAG/T1≤3.958. 